For monitoring temperature parameters of product testing method
Based on the principle of NTC thermistor temperature monitoring is monitor the necessary care on one of the parameters, especially in the long time, temperature trend monitoring has an important clinical significance, but in real-time temperature measurement, because thermistors heat balance response time slow and lead to measure temperature response when time is too long and limit the measuring method of measuring temperature in the scope of application, such as the patient's temperature outpatient service quickly check, hospitalization of patients conventional temperature measurement, etc. But this method has high accuracy measuring scope width and the characteristics of the procedure, and can be widely used in the treatment of high and low temperature for a long time the result of temperature monitoring, at present had the thermistors principle, and has a quick response temperature measurement method used in measuring temperature.
2. The temperature measuring principle and method
Based on the principle of thermal resistor temperature measurement is for heat-sensitive sensor and human body after contact with the thermal equilibrium heat-sensitive sensor resistance to the influence degree of the body temperature to obtain information, the body temperature circuit driver partly to the specific on heat-sensitive sensor constant current, will heat-sensitive sensor of the resistance change converted into voltage change, again through the amplification, filter based on software and the signal transformation to further value and different temperature sensor will produce a different signal transformation form, the most common is the United States YSI temperature probe, YSI compatible probe, domestic and other brand temperature probe, this is a kind of direct signal measurement method, measurement accuracy or not will be totally depends on temperature signal amplifier circuit and constant current source driver circuit design, and the characteristics of temperature heat-sensitive sensor, thus the measurement of body temperature parameters performance evaluation should be divided into two parts, one is for temperature of amplifier circuit test evaluation, and the second is for heat-sensitive sensor test evaluation, the first part of the circuit can be evaluated according to the characteristics of the software installed by WenMin sensor characteristics in turn set up different precise resistance to test the accuracy of the temperature measurement circuit, which is now in its most monitor product specification of the given index, the second part of the heat-sensitive sensor inspection can be in completing the first step on the basis, usually by waters contrast method.
3. Measuring temperature assay methods
A. body temperature simulator test
Now most of the parameters of the signal simulator no temperature test function. So, usually in the laboratory test process through the use of precision resistance box as a resistance to simulate different temperature change source of the resistance, and the temperature amplifier circuit lab test, can complete temperature measurement circuit and based on specific characteristics of heat-sensitive sensor software algorithm temperature measurement range and accuracy of evaluation; By using the method of water to the constant temperature box, thermal sensor and precision temperature tester can be finished for temperature measurement circuit and the whole of the WenMin sensor measurement precision, scope and the response time evaluation, there is another consideration in the operating room temperature measurement of the expected application in laboratory tests should be taken into special consideration in the operation of high-frequency electrotome may to measuring temperature affected testing project.
According to the above description, based on the thermal characteristics of laboratory tests for temperature measurement methods will emphasize on:
1. The body temperature measurement range and accuracy of the circuit;
2. Temperature circuit and the whole of the heat-sensitive sensor measurement range and accuracy and response time;
3. The operation of high frequency electric knife can be used to measuring temperature circuit effect.
B. temperature clinical testing
According to body temperature probe and the method of measuring temperature intended use, pointed out the clinical correlation plan to choose the right equipment, test and CST than body temperature and probe "the same site" installation position, synchronous data record, and other basic means, in plan should also be mentioned in the special operating room temperature monitoring application function as using high frequency electric knife surgery likely to the influence of the temperature measurement, ensure the temperature probe clinical contrast the reliability of data, give clear contrast analysis report, validate temperature monitoring function in the validity of the intended use.
4. Temperature characteristics of the inspection procedure and content
Measuring temperature is based on the change of the thermal resistor to get the corresponding temperature value, its measurement range and accuracy will depend on the temperature measurement circuit and temperature sensor, in laboratory evaluation will consider mainly the accuracy of the temperature measurement circuit and frequency response characteristics, and the measurement of body temperature probe by the body temperature probe accuracy of the manufacturers warranty, provide specifications and test report.
B. basic indicators and standards and regulations
1. The basic indicators: measurement range, measurement accuracy, response time.
2. Standards and regulations: international designed mark, EN12470-4 2000, "Clinical thermometers-Part4: Performance of electrical thermometers for continuous measurement".
C. inspection methods
1. The equipment precision resistance box, the constant temperature box, body temperature probe, connecting cables and has the characteristics of thermal resistor based on measuring temperature function of the monitor, high-frequency electrotome and accessories.
2. The test contents and methods: first the reference standard stipulated in the test method; Next is the enterprise standard reference on the test method; Inspection contents should include the basic measuring parameters and other relevant safety index; Set of hf electrotome power and the appropriate connection form, start high frequency electric knife, observation high-frequency electrotome can affect the body temperature readings.
D. results and through the principle of it or not
1. The first all test must meet the related standard and special in the terms of the corresponding standard.
2. All test must satisfy the enterprise standard corresponding terms, the enterprise level cannot under the above standards.
This special need explanation is temperature measurement precision, usually most monitor production company which offers temperature measurement accuracy specification refers to the circuit under normal temperature, the temperature in the use of precision resistance box from the evaluation results, the precision does not contain the body temperature resistance probe.